#include <bits/stdc++.h>
using namespace std;
const int EXP = 1e-6;
int main()
{
    ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
    long long n;
    cin >> n;
    long long d = sqrt(n);
    if(n < 0) cout << 0 << endl;
    else if(d * d == n) cout << n << endl;
    else cout << (d + 1) * (d + 1) << endl;
    return 0;
}